Leanpub Header

Skip to main content

Astrophysics for the Rest of Us: Fundamentals

AftRoU: Fundamentals

What does it really mean to “observe” the Universe? This course trains you to think like an observational astronomer, moving from intuition to first-principles reasoning about light and matter, plus interactions between them. You will build a coherent picture of astrophysics by following real observational clues and turning data into explanations.

Minimum price

$25.00

$25.00

You pay

$25.00

Author earns

$20.00
$

...Or Buy With Credits!

You can get credits with a paid monthly or annual Reader Membership, or you can buy them here.
PDF
EPUB
About

About

About the Course

Astrophysics is not just pretty pictures. What happens when we go beyond awe and start asking why the universe must behave the way it does?

Astrophysics for the Rest of Us: Fundamentals invites you to explore the cosmos from first principles — not as a list of disconnected facts, but as a logical unfolding of what must happen Astrophysics is not just pretty pictures. What happens when we go beyond awe and start asking why the universe must behave the way it does?

Astrophysics for the Rest of Us: Fundamentals invites you to explore the cosmos from first principles — not as a list of disconnected facts, but as a logical unfolding of what must happen when light and matter interact under the rules of physics.

We’ll begin with the most basic question — what does it mean to “see” something? — and walk step by step through how we gather information from the universe. From photons falling into telescopes to the fingerprints of atoms in starlight, you’ll learn how we extract meaning from distant messengers.

This course doesn’t assume you’re a physicist. What it assumes is that you’re curious, thoughtful, and willing to slow down and think things through. We emphasize conceptual understanding, plain language, and building your own reasoning from the ground up. You’ll walk in the shoes of astronomers, wrestle with cosmic puzzles, and come away with a deep, working intuition for how astrophysics actually works.

Whether you’re preparing for more advanced coursework, teaching others, or simply hungry to understand the universe for yourself, this is your starting point.

Note: this material is intended as a required resource for a college course.

We’ll begin with the most basic question — what does it mean to “see” something? — and walk step by step through how we gather information from the universe. From photons falling into telescopes to the fingerprints of atoms in starlight, you’ll learn how we extract meaning from distant messengers.

This course doesn’t assume you’re a physicist. What it assumes is that you’re curious, thoughtful, and willing to slow down and think things through. We emphasize conceptual understanding, plain language, and building your own reasoning from the ground up. You’ll walk in the shoes of astronomers, wrestle with cosmic puzzles, and come away with a deep, working intuition for how astrophysics actually works.

Whether you’re preparing for more advanced coursework, teaching others, or simply hungry to understand the universe for yourself, this is your starting point.

Note: this material is intended as a required resource for a college course.

Share this course

Instructor

About the Instructor

Toshiya Ueta

Material

Course Material

  • Chapter 1 What is Astronomy?

  • Section 1.1 How We Do Astronomy: From What We See to What We Know

  • Section 1.1 Multiple Choice Quiz

    3 attempts allowed

  • Section 1.1 Fill-in-the-Blanks Quiz

    3 attempts allowed

  • Section 1.1 Short Answer Exercise

  • Section 1.2 Messengers: How the Universe Speaks to Us

  • What are Messengers?

  • Light (Electromagnetic Radiation)

  • Cosmic Rays

  • Neutrinos

  • Gravitational Waves

  • How Do Messengers Arise?

  • Section 1.2 Multiple Choice Quiz

    3 attempts allowed

  • Section 1.2 Fill-in-the-Blanks Quiz

    3 attempts allowed

  • Section 1.2 Short Answer Exercise

  • Section 1.3 Messengers: Their Journey Across the Universe

  • The Journey of Messengers

  • What Happens Along the Way?

  • Consequences for Astronomy

  • Section 1.3 Multiple Choice Quiz

    3 attempts allowed

  • Section 1.3 Fill-in-the-Blanks Quiz

    3 attempts allowed

  • Section 1.3 Short Answer Exercise

  • Section 1.4 Messengers: How We Capture Their Signal

  • Electromagnetic Wave Astronomy

  • Cosmic Ray Astronomy

  • Neutrino Astronomy

  • Gravitational Wave Astronomy

  • Multi-Messenger Astronomy

  • Astronomy as Science

  • Section 1.4 Quiz

    3 attempts allowed

  • Section 1.4 Fill-in-the-Blanks Quiz

    3 attempts allowed

  • Section 1.4 Short Answer Exercise

  • Section 1.5 Chapter Summary

  • Glossary of Important Terms

  • Chapter 2 Light

  • Section 2.1 Properties of Light

  • Light as Electromagnetic Waves

  • Speed of Light

  • Light as Particles

  • Electromagnetic Spectrum

  • Summary of the Electromagnetic Spectrum (boundaries are just for reference!!)

  • Section 2.1 Multiple Choice Quiz

    3 attempts allowed

  • Section 2.1 Fill-in-the-Blanks Quiz

    3 attempts allowed

  • Section 2.1 Short Answer Exercise

  • Section 2.2 Seeing to Pinpointing: Coordinate Systems

  • Understanding the Celestial Sphere

  • Defining Coordinate Systems for the Sky

  • Defining Angular Separation

  • Defining Solid Angles

  • Section 2.2 Multiple Choice Quiz

    3 attempts allowed

  • Section 2.2 Fill-in-the-Blanks Quiz

    3 attempts allowed

  • Section 2.2 Short Answer Exercise

  • Section 2.3 Seeing to Measuring: Photometry

  • Assumptions

  • Luminosity

  • Flux

  • Specific Flux / Flux Density

  • Intensity / Surface Brightness

  • Photometry: Measuring Brightnesses

  • Apparent Magnitudes

  • Standard Apparent Magnitudes and Their Zero-Points

  • Absolute Magnitudes

  • Spectral Energy Distribution (SED)

  • Color: A Closer Look into the Spectrum

  • Section 2.3 Multiple Choice Quiz

    3 attempts allowed

  • Section 2.3 Fill-in-the-Blanks Quiz

    3 attempts allowed

  • Section 2.3 Short Answer Exercise

  • Section 2.4 Seeing to Analyzing: Spectroscopy

  • Spectroscopic Measurements

  • Kirchhoff’s Laws of Spectroscopy

  • Spectral Resolution

  • Optical/Visible Spectroscopy

  • Infrared Spectroscopy

  • Ultraviolet (UV) Spectroscopy

  • Radio Spectroscopy

  • X-ray Spectroscopy

  • Spectral Resolution in Photometry

  • Section 2.4 Multiple Choice Quiz

    3 attempts allowed

  • Section 2.4 Fill-in-the-Blanks Quiz

    3 attempts allowed

  • Section 2.4 Short Answer Exercise

  • Section 2.5 Chapter Summary

  • Glossary of Important Terms

  • Chapter 3 Matter

  • Section 3.1 Atoms

  • Sub-Atomic Particles

  • Atomic Structure

  • Four Forces of Nature

  • Periodic Table of the Elements

  • Isotopes

  • Chart of Nuclides

  • Ions, Ionization, and Ionization States

  • Section 3.1 Multiple Choice Quiz

    3 attempts allowed

  • Section 3.1 Fill-in-the-Blanks Quiz

    3 attempts allowed

  • Section 3.1 Short Answer Exercise

  • Section 3.2 Kinetic Theory

  • Key Assumptions

  • Kinetic Energy

  • Temperature

  • Pressure

  • Section 3.2 Multiple Choice Quiz

    3 attempts allowed

  • Section 3.2 Fill-in-the-Blanks Quiz

    3 attempts allowed

  • Section 3.2 Short Answer Exercise

  • Section 3.3 Phases of Matter

  • Liquid Phase

  • Solid Phase

  • Gas Phase

  • Plasma Phase

  • At Even Higher Energies…

  • Degenerate Phase

  • Electron Degeneracy, Neutron Degeneracy, and Singularity

  • Section 3.3 Multiple Choice Quiz

    3 attempts allowed

  • Section 3.3 Fill-in-the-Blanks Quiz

    3 attempts allowed

  • Section 3.3 Short Answer Exercise

  • Section 3.4 Chapter Summary

  • Glossary of Important Terms

  • Chapter 4 Light-Matter Interactions

  • Section 4.1 Fundamentals of Radiative Transfer

  • Initial Setup of the Problem

  • Loss of Radiation by Scattering and Absorption

  • Generalized Cross Section

  • Opacity

  • Optical Depth and Photon Mean Free Path

  • Gain of Radiation by Scattering and Emission

  • Scattering of the Ambient Radiation Field

  • Emission by the ISM

  • Summary of Radiation Gain and Loss So Far

  • Formal Solution of the Radiative Transfer Equation

  • Simplified Case of Uniform Optical Depth

  • Practical Considerations in Astrophysical Observations

  • Extinction Correction

  • Section 4.1 Multiple Choice Quiz

    3 attempts allowed

  • Section 4.1 Fill-in-the-Blanks Quiz

    3 attempts allowed

  • Section 4.1 Short Answer Exercise

  • Section 4.2 Microphysics of Emission and Absorption

  • Thermal Emission

  • Blackbody Radiation

  • Low-Temperature Limit

  • High-Temperature Limit

  • Monotonicity with Temperature

  • Wien’s Displacement Law

  • Stefan–Boltzmann Law

  • Atomic Energy Levels and Electron Transitions

  • Matter-Waves and Discrete Atomic Electron Shells

  • Electron Energy Levels

  • Atomic Electron Transitions

  • Line Emission and Absorption by Atoms

  • Line Emission

  • Line Absorption

  • Kirchhoff’s Laws of Spectroscopy: a Reprise

  • Practical Example

  • Going Deeper into the Quantum Realm

  • Line Emission and Absorption by Molecules

  • Section 4.2 Multiple Choice Quiz

    3 attempts allowed

  • Section 4.2 Fill-in-the-Blanks Quiz

    3 attempts allowed

  • Section 4.2 Short Answer Exercise

  • Section 4.3 Chapter Summary

  • Glossary of Important Terms

  • Chapter 5 Observations

  • Section 5.1 Telescopes

  • Telescopes as Photon Buckets

  • Refracting Telescopes

  • Telescopes as Magnifying Glasses

  • Reflecting Telescopes

  • Telescope Mounts

  • Evolution of the Telescope Aperture Size

  • Adaptive Optics

  • Interferometric Observations

  • Section 5.1 Multiple Choice Quiz

    3 attempts allowed

  • Section 5.1 Fill-in-the-Blanks Quiz

    3 attempts allowed

  • Section 5.1 Short Answer Exercise

  • Section 5.2 Detectors

  • Detector as a Photon Bucket Brigade

  • Detector as a Photon-to-Electron Converter

  • Section 5.2 Multiple Choice Quiz

    3 attempts allowed

  • Section 5.2 Fill-in-the-Blanks Quiz

    3 attempts allowed

  • Section 5.2 Short Answer Exercise

  • Section 5.3 Imaging

  • Section 5.3 Multiple Choice Quiz

    3 attempts allowed

  • Section 5.3 Fill-in-the-Blanks Quiz

    3 attempts allowed

  • Section 5.3 Short Answer Exercise

  • Section 5.4 Photometry

  • Photometric Calibration

  • Calibrating the Measurements

  • Why Calibration Matters

  • Section 5.4 Multiple Choice Quiz

    3 attempts allowed

  • Section 5.4 Fill-in-the-Blanks Quiz

    3 attempts allowed

  • Section 5.4 Short Answer Exercise

  • Section 5.5 Spectroscopy

  • Spectral Resolution

  • Wavelength and Flux Calibration

  • Doppler Measurements

  • Section 5.5 Multiple Choice Quiz

    3 attempts allowed

  • Section 5.5 Fill-in-the-Blanks Quiz

    3 attempts allowed

  • Section 5.5 Short Answer Exercise

  • Section 5.6 Spectral Imaging

  • Section 5.6 Multiple Choice Quiz

    3 attempts allowed

  • Section 5.6 Fill-in-the-Blanks Quiz

    3 attempts allowed

  • Section 5.6 Short Answer Exercise

  • Section 5.7 Chapter Summary

  • Glossary of Important Terms

The Leanpub 60 Day 100% Happiness Guarantee

Within 60 days of purchase you can get a 100% refund on any Leanpub purchase, in two clicks.

Now, this is technically risky for us, since you'll have the book or course files either way. But we're so confident in our products and services, and in our authors and readers, that we're happy to offer a full money back guarantee for everything we sell.

You can only find out how good something is by trying it, and because of our 100% money back guarantee there's literally no risk to do so!

So, there's no reason not to click the Add to Cart button, is there?

See full terms...

Earn $8 on a $10 Purchase, and $16 on a $20 Purchase

We pay 80% royalties on purchases of $7.99 or more, and 80% royalties minus a 50 cent flat fee on purchases between $0.99 and $7.98. You earn $8 on a $10 sale, and $16 on a $20 sale. So, if we sell 5000 non-refunded copies of your book for $20, you'll earn $80,000.

(Yes, some authors have already earned much more than that on Leanpub.)

In fact, authors have earned over $14 million writing, publishing and selling on Leanpub.

Learn more about writing on Leanpub

Free Updates. DRM Free.

If you buy a Leanpub book, you get free updates for as long as the author updates the book! Many authors use Leanpub to publish their books in-progress, while they are writing them. All readers get free updates, regardless of when they bought the book or how much they paid (including free).

Most Leanpub books are available in PDF (for computers) and EPUB (for phones, tablets and Kindle). The formats that a book includes are shown at the top right corner of this page.

Finally, Leanpub books don't have any DRM copy-protection nonsense, so you can easily read them on any supported device.

Learn more about Leanpub's ebook formats and where to read them

Write and Publish on Leanpub

You can use Leanpub to easily write, publish and sell in-progress and completed ebooks and online courses!

Leanpub is a powerful platform for serious authors, combining a simple, elegant writing and publishing workflow with a store focused on selling in-progress ebooks.

Leanpub is a magical typewriter for authors: just write in plain text, and to publish your ebook, just click a button. (Or, if you are producing your ebook your own way, you can even upload your own PDF and/or EPUB files and then publish with one click!) It really is that easy.

Learn more about writing on Leanpub